Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Graphene, a generally planar monolayer array of carbon atoms, may be grown using chemical vapor deposition (CVD) on substrate surfaces coated with nickel (Ni), ruthenium (Ru), or copper (Cu) layers. However, defects in graphene production, such as the nucleation of multilayer graphene, may occur at metal grain boundaries in a graphene substrate's growth layer. Control of the morphology of the growth layer may improve the morphology of graphene films by limiting the number of metal grain boundaries and hence the occurrence of production defects such as multilayer graphene.
Directional crystallization (also known as Excimer Laser Annealing) has been used to control the morphology of silicon (Si) layers in Active Matrix Liquid Crystal Display (AMLCD) devices. Using this technique, amorphous or poly-Si material may be transformed to large grain Si by melting a Si layer in a narrow region in a few nanoseconds. By scanning a laser across a film surface, molten regions may nucleate on already cooled regions allowing film grains to grow and extend in the direction of the laser motion. A single pass may produce elongated grains in the film. A second pass perpendicular to the first pass may produce large equiaxed film grains.